Apparatus for treating tubular bodies



AIPAmvrUsv Fon TREATING TUBULAR BODIES Patented Oct. 19, 1948 OFFICEAPPARATUS Fon TREA'rING 'rUBULAR BODIES Frank A. Schratt, Cincinnati,Ohio;

Application May 5, 1945, Serial No. 592,203

4 Claims.

The present invention relates to apparatus for treating cylindrical andtubular bodies and has for an object the provision of a simple andsturdy mechanism whereby the inside and outside surfaces of tubularbodies, or either of such surfaces may be uniformly treated to theaction of fluid pressure nozzles for such purposes as sand blasting inorder to clean, abrade, or etch the said surface o-r surfaces or forotherwise treating the same.

A further object of the invention is to provide apparatus that is simpleand inexpensive to operate and entirely reliable Iand accurate in itsoperation.

A still further object of the invention is to provide apparatus of thischaracter which automatically correlates combined rotation andlongitudinal movement of the body thereby acted upon.

Another object o-f the invention is to provide a safe and simpleapparatus for the removal of deposits from the surfaces of metal tubesafter heat treatment thereof.

These and other objects are attained by the means described herein andexemplified in the accompanying drawings, in which;

Fig. l is a side elevational view showing apparatus embodying theinvention, the wall of the dust chamber being cut away and shown incrosssection, and the pneumatic control mechanism being showndiagrammatically.

Fig. 2 is a top plan View of the apparatus of Fig.,1, the dust chamberbeing cut away and shown in cross-section and the pneumatic controlbeing omitted.

Fig. 3 is a cross-sectional view taken on line 3-3 of Fig. 1, butshowing a tube to be blasted in position on the carriage and alsoshowing the nozzles adjusted for simultaneously sand blasting the insideand outside surfaces.

Fig. 4 is an end elevational view of the dust chamber of Figs. 1 3showing the pneumatic control mounted thereon.

Fig. 5 is a longitudinal, cross-sectional view of a blast nozzle of theapparatus of the invention.

Fig. 6 is an end elevational view ofa uniformly adjustablenozzle-holding bracket forming ay detail of the invention.

Fig. '1 is a side elevational View of the device of Fig. 6.

Heretofore numerous diiculties have presented themselves in thetreatment of the surfaces of cylindrical and tubular bodies, amongstthese being the time required for mounting of such bodies for rotationabout the axis thereof and the provision for the movement of a suitabletool in a relatively axial direction. As a specific example of aparticularly difcult task the apparatus of the invention is hereinexemplified in an arrangement for removing the very hard carbon depositsfrom lengths of previously heat treated vsteel tubing of comparativelysmall inside diameter. In general, the invention consists in providing awork holding truck I0 and a power truck Il both tractionally mounted oncontinuous straight tracks I2 and connected together for uniform travelin spaced relation by a tie rod I3 which is slightly longer than thetube or cylinder I4 to be operated upon. The trucks I0 and II areprovided with grooved wheels I5 to insure rectilinear motion on thetracks I2. Substantially one-half the length of the tracks I2 is locatedwithin a dust chamber I6 of approved construction and arranged withvents I1 near the bottom thereof which are connected to a suitable airexhaust system I8. The end wall I9 of dust chamber I6 has a suitablepacking gland 20 through which the tie rod I3 may pass withoutpermitting the escape of dust or airborne material from chamber I6. Thetie rod I3 is bolted or otherwise secured at its opposite ends tocrossmembers 2| and 22 of trucks I0 and II respectively. Rigidly mountedintermediate tracks I2, exteriorly of and adjacent the end wall I9 is anair cylinder 23 which has its axis in a common vertical plane with thetie rod I3. Within cylinder 23 is a piston 24 to which is connected apiston rod 25 whichextends beneath and beyond the truck II. The pistonrod 25 has on its extreme louter end an upturned, U-shaped member 26which is rigidly connected in substantial alignment with the tie rod I3by bolting or otherwise fastening it to a cross member 21 of truck I I.As

`the piston 24 reciprocates in the cylinder 23, the

truck II moves from the position shown in Fig. 1 to a position over thecylinder 23during which time the tie rod I3 pushes the truck or workcarriage I0 away from the wall I9 to approximately the opposite end ofchamber I6.

Mounted on truck II is an electric motor 28 which drives a variablespeed reducer mechanism 29 of any suitable design from which operates asecond speed reducer 3l). A shaft 3| is thus rotatable at apredetermined selected speed. The shaft 3| has a coupling 32 thereonwhich connects with coupling 33 on a shaft 34. Shaft 34 passes throughend wall I3 of chamber I6 and is surrounded by another dust tightpacking gland 20. Interiorly of chamber I3, shaft 34 is connected to theend of a short projecting shaft Y35 of a roller 36 by means of acoupling indicated generally at 31. Roller 36 is mounted for axialrotation on the work carriage IB and a freely rotating companion roller38 is journaled in spaced parallelism thereto upon carriage Ill. Thetube or work piece I4 to be abraded, cleaned or otherwise treated issupported on and disposed between power roller 36 and free roller 38 andhas tangential contact therewith throughout the length thereof.

From the foregoing it will be apparent that with a tube or cylinder I4resting on the rollers, power rotation of roller 36 from motor 28 willre- Vsult in a rotation of the work I4 about its own longitudinal axiswhile recipreeation of truck II will move the work carriage I0 along thetracks I2 to eiect longitudinal recprocation of the work in thedirection of its longitudinal axis. The arrangement in Figs. 1, 2 and 3provides for the simultaneous treatment, i. e. sand blasting of theinside and outside surfaces of a tubular body. For blasting the insidesurface of the tube, a straight, rigid pipe 39 with a blast nozzle 40 onthe end thereof is clamped adjacent its opposite end in a collar 4I onan adjustable bracket 42 which is in turn rigidly and adjustably mountedon a truss 43, the base 44 of which is desirably bolted or otherwisesecured to tracks I2. The bracket (see Fig. 6) may have elongatedbolting slots 45 therein to provide a desired degree of elevationaladjustment of the pipe 39, A sand blast hose 46 is adapted to beconnected at its one end to any suitable source of abrasive and pressureair (not shown) while the opposite end enters chamber I6 and isconnected to the end of pipe 39 which projects through collar 4I. By thehereinbefore described arrangement it is possible to remove deposits ormaterial from the inside surface of a tube such as I4, the insidediameter of which is notgreatly in excess of the diameter of the nozzleon the pipe. A very accurate degree of deposit or material removal isattained by adjusting the rotational speed of shaft 34 and the rate oflongitudinal travel of the piston 24 in cylinder 23. The rotary speedadjustment is effected by shifting the manual lever 4l of theconventional Variable speed reducer 29. The adjustment of thelongitudinal travel of work carriage I0 is effected by regulating thespeed of piston travel, particularly during the cutting or blastingmovement of the tube I4.

It is desirable for expediting the work to `arrange for rapid return orwithdrawal of the tube from over the nozzle 40' to permit the finishedwork to be removed and replaced with another piece in a minimum of timeafter the blasting operation is complete. This requires that themovement of piston 24 from the piston shown at the right-hand end ofcylinder 23 to the opposite end of the cylinder be made slow and thatthe return movement shall be quite rapid but without undue impact. Thisis conveniently arranged for by utilizing an adjustable pneumaticcontrol as shown-for example in United States Patent Nos. 840,876 and840, 877 and indicated .diagrammatically at 48. According to the presentarrangement of said prior patented control the cylinder 23 is securedhorizontally and its piston rod 25 Y reciprocates in parallelism withtracks I2, An air pressure supply line 49 connects with a Valve 50operable by lever 5I to connect supply line 49 with the pipe 52 whichleads to the left-hand end of cylinder 23, while pipe 53, leading to therighthand .end of the cylinder is closed off from the pressure supplypipe 49 but is vented to the atmosphere. As shown in Fig. 1 the lever 5Iis set in reverse position and the truck II has just completed itsmovement to the right-hand limit. The pipes 52 and 53 serve alternatelyas supply and exhaust pipes in the pneumatic control of thereciprocating movement. Pipe 52 has a pair of Oneway by-pass valves 54and 55 controlling the flow of pressure and exhaust air in oppositedirections therethrough. Pipe 52 has a similar set of adjustable Oneway,by-pass valves 56 and 51.

When the apparatus is to be operated, a tube such as I4 is placed onrollers 36 and 38 Wl'ilGh serve to automatically center the work betweenthem. The bracket 42 is now adjusted vertically and laterally until thenozzle 4I) will be received by the hollow interior of the tube when thetube `is reciprocated. It is preferred that the nozzle be disposedeccentrically of the tube as shown, for example, in Fig. 3. During theadjustment of the apparatus lever 5I is left in a vertical or neutraposition wherein pressure from pipe 49 `is completely closed off fromboth of the pipes 52 and 53. Operation is begun by energizing motor 28which serves to drive roller 36 in a clockwise direction as viewed inFig. 3 whereupon the tube i4 is caused to rotate in a `counterclockwisedirection and this in turn causes the supporting freely rotatable roller38 to turn inthe same direction as the power roller 36. The sand blastapparatus (not shown) is now turned on to supply an abrasive blastthrough hose 46 and nozzle 40 and the lever 5I is moved to the forwardposition as shown in dotted lines in Fig. 1 whereupon power truck II andwork Icarriage I0 are slowly moved toward the left while the work isrotated on its axis as it is moved. 'Ihe blast from the nozzle 40 thustraces a very close pitched spiral of sand 'blast upon the inside oftube I4 generally comparable to an interior, material removing cut of atool in a lathe. The `adjustable valves 55 an-d 55 are regulated so thatthe incom-v ing pressure air through pipe 53 entering behind the pistonand the exhaust air passing from the .front of the piston through pipe52 to the atmosphere, may travel at substantially uniform slow rate.When the truck II has reached the limit of movement and the tube `I4 haspassed completely over the nozzle 40, piston 24 has expended its slowpower stroke and an adjustable Vstop 58 on the tie rod is ready toengage the wall I9. The lever 5I is now thrown manually or otherwise tothe position shown in full lines in Fig. 1 whereupon the pressure air,as regulated by adjusting valve 54, passes at a 'higher rate throughpipe 52 and is exhausted at a comparable rate from the opposite end ofthe cylinder through pipe 53 and the regulator valve 5l. This operationrapidly moves carriage II) to the position shown in Fig. l and withdrawsthe tube from over nozzle 4U. At this instant lever 5I is moved to anintermediate or neutral position to shut oi the longitudinal movement ofthe carriage by the piston.

The removal of stubborn and hard deposits from the interior ofrelatively small tubes has been a very diilicult task when conventionboring apparatus has been used. The present apparatus is thus highlyadvantageous for this type of operation since there is no difflcultlyused tool in danger of becoming rapidly dull and frequently broken. Theblast abrasive and the material removed is forced through the tube andallowed to fall from the trailing end thereof.

It is frequently desired to remove carbon deposits or the like from bothoutside and inside surfaces of a tube, and this is accomplished silmultaneously by utilizing the nozzle 40 as afore- .described andproviding a bracket 42 as shown in Fig. 6 on the side wall of chamber I6 and securing a sand blast pipe 58 with a blast nozzlel yfrom nozzle 40will not meet or play upon the bodies of the nozzles when no workintervenes in the paths of the abrasive blasts.

Any suitable means may be provided for automatically shutting off thepower to motor 23 when power truck ll reaches the end of its returntravel against stops 6|. For example, an electric limit switch 62 may beconnected into the power cable circuit 63 and mounted on one of thestops 6| for actuation by the return movement of truck Il.

The apparatus as previously indicated may be utilized for a variety ofoperations e. g. for etching or sand blasting the interior surface of atube of` metal, glass or other material. By adjusting the return oflongitudinal feed to a greater or lesser speed and also by adjusting therotational speed it is possible to effect a greater or lesser degree ofmaterial or deposit removal; or if desired, to produce a distinct etchedspiral on either inside or outside surfaces of the tube. ting off thelongitudinal feed and utilizing the rotational drive, band-like areasmay be sand blasted to the exclusion of adjacent parts. By deenergizingmotor 28 and utilizing the pneumatic reciprocating mechanism only, astraight longitudinal sand blast strip may be produced upon the insideor outside surface of a tube. In any event, the apparatus when properlyadjusted can be relied upon to perform uniformly identical operationsupon a series of similar tubes or cylinders. l.

Access to the chamber i 6 may be through a suitable door such as 64placed at any convenient location in the chamber.

In order to baille and deflect the velocity sand blast, spray or othermedium which is discharged from nozzle oran equivalent element, a sheetmetal deector such as 65 is suitably secured to the work carriage I 0.

While the apparatus and method has been herein described in connectionwith sand blasting .f

as a specific operation, it is to be understood that other surfacetreatment operations may be performed on tubular or cylindrical bodiesby utilizing any other type of spray, brush or applicatorinstrumentality in lieu of the sand blast. It will also be understoodthat one or more nozzles, sprays, applicators, or the like, of the sameor different character may be grouped and mounted with relation tonozzles 40 and 59 or their equivalents so as to effect one type ofsurface treatment operation on the surface of the tube in advance ofanother and thus complete several operations on a given surface of atube or cylinder in a single cycle of movement thereof.

What is claimed is:

1. Apparatus of the class described comprising supporting track members,a power truck supported on said track members, a work carriage supportedon said track members, a tie rod connecting said truck and carriage andretaining them in predetermined spaced relation, rotary power meanscarried by the power truck, a pair of spaced apart rollers journaled onthe carriage and arranged for constant parallel relation with each otherand with said tracks, a power shaft connected at its opposite ends tothe power means and one of said rollers, means for reciprocating thesaid truck and carriage at predetermined rates of speed along said trackmembers, a first sand blast pipe, means for supporting said pipe inadjusted positions with relation to the ends of the rollers and parallelthereto, a second sand blast pipe and means for supporting said secondsand blast pipe with its discharge in predeter- By shutmined relation tothe corresponding end of the iirst mentioned sand blast pipe.

2. Apparatus of the class described comprising a pair of parallel trackelements, a dust chamber surrounding a portion of said tracks at oneend, a work carriage tractionally supported on said tracks within thedust chamber, a power truck tractionally supported on said tracksexteri-orly of 'the chamber, a tie rod passing slidably through th-ew-all of the dust chamber and rigidly connecting said work carriage andsaid truck in spa-.ced relation, variable speed power means mounted onthe truck, a pair of rollers mounted in spaced side by side relationupon the work carriage in parallelism with the tracks, a drive shaftpassing through the wall Iof the dust -chamber and rotatably connectingone 4of said rollers with said power means, means disposed exteriorly`of the chamber for reciprocating said truck and carriage in unisonalong said :track members, and means including a sand blast nozzle and:an adjustable support therefor for xedly holding said nozzle inpredetermined relation to the truck for operating on a body supported onsaid rollers on said work carriage.

3. In combination a pair of parallel track members, a power trucktractionally supported thereon, a pneumatic -cylinder rigidly mountedbetween the tracks and having a piston reciprocable in 'the cylinder, anextended piston rod on said piston and connected to said truck, Vatractionally supported work carri-age connec-ted in spa-ced relation tosaid truck for moving in unison therewith under the action of the pistonin the cylinder, a pair of n-oncontacting work support rollers on saidcarri-age; means for driving one of said rollers at a selected speed andmeans for xedly mounting a surface treatment instrumentality inpredetermined relation .with respect to the path of travel of a bodysupported yon said rollers.

4. In combination a pair of parallel track members, a power trucktractionally supported thereon, a Ipneumatic ycylinder rigidly mountedbetween the tracks and having a piston reciprocable in the cylinder, anextended piston rod on said piston and connected to said truck, atractonally supported work carriage on said track, transund-er theaction of the piston in the cylinder,

tube supporting rollers on said carriage, power means on said powertruck, a rotatable connection from said power means on said truckextending in dust tight relation through said barrier and connectingwith one of the tube supporting rollers, yand means for xedly mounting asurface treatment instrumentality with respect to the path of travel ofa tube supported on said rollers. K

FRANK A. SCI-TRATT.

REFERENCES CITED The following references are of record in the NumberNumber

